I have to agree. I developed a proprietary embedded web server using a streaming HTTP parser. Complying with the HTTP parsing rules is a headache to say the least. Variable amounts of whitespace; 2 variants of line terminators (\r\n or \n) with the provision that the latter SHOULD be accepted by the server and line continuations make complying with the whole specification a real pain if you only have 100 bytes to parse pieces of your request.

Maybe for a server with massive resources (I am talking about megabytes of RAM compared to kilobytes I work with) being liberal in what you accept works, but not when you are on a budget.